Methods for synthesizing stereoselectively polycyclic compounds having a quaternary asymmetric carbon in an internuclear position are very few and have so far been scarcely known.
Polycyclic compounds are contained in physiologically active compounds and functional materials in many cases. For example, some substituted anthraquinone compound has so far been known as a dye. For example, compounds which have an amino group, an alkylamino group or an arylamino group in an α-position of anthraquinone and which have a sulfonic acid group in the other positions are publicly known as anthraquinone base acidic dyes. Specifically, Anthraquinone Iris R, Anthraquinone Violet RN, 3RN, Anthraquinone Blue RXO and Anthracyanine are produced and marketed as dyes. Applications as an antitumor agent and a photographic material are found for some kind of anthraquinone compounds.
Thus, polycyclic ketone compounds having an anthraquinone skeleton have various industrially useful applications, but so many synthetic processes which are satisfactory in terms of reaction conditions, a number of reaction steps and application ranges are not necessarily available. Accordingly, desired is a process for synthesizing stereoselectively polycyclic ketone compounds having various anthraquinone skeleton.